1 //! Audio output in WAV format.
2 use nihav_core::io::byteio::*;
3 use nihav_core::frame::*;
6 /// WAVE output writer.
7 pub struct WavWriter<'a> {
8 io: &'a mut ByteWriter<'a>,
12 fn write_byte(wr: &mut ByteWriter, sample: u8) -> ByteIOResult<()> {
16 fn write_s16(wr: &mut ByteWriter, sample: i16) -> ByteIOResult<()> {
17 wr.write_u16le(sample as u16)
20 fn write_s32(wr: &mut ByteWriter, sample: i32) -> ByteIOResult<()> {
21 wr.write_u16le((sample >> 16) as u16)
24 fn write_f32(wr: &mut ByteWriter, sample: f32) -> ByteIOResult<()> {
25 let mut out = (sample * 32768.0) as i32;
26 if out < -32768 { out = -32768; }
27 if out > 32767 { out = 32767; }
28 if out < 0 { out += 65536; }
29 wr.write_u16le(out as u16)
32 macro_rules! write_data {
33 ($wr:expr, $buf:expr, $write:ident) => ({
34 let len = $buf.get_length();
35 let ainfo = $buf.get_info();
36 let nch = ainfo.get_channels() as usize;
37 let mut offs: Vec<usize> = Vec::with_capacity(nch);
38 for ch in 0..nch { offs.push($buf.get_offset(ch)); }
39 let is_planar = $buf.get_step() == 1;
40 let data = $buf.get_data();
45 let sample = data[offs[ch] + i];
58 impl<'a> WavWriter<'a> {
59 /// Constructs a new `WavWriter` instance.
60 pub fn new(io: &'a mut ByteWriter<'a>) -> Self {
61 WavWriter { io, data_pos: 0 }
63 /// Writes audio format information to the file header.
65 /// This function should be called exactly once before writing actual audio data.
66 pub fn write_header(&mut self, ainfo: NAAudioInfo) -> ByteIOResult<()> {
67 let bits = ainfo.get_format().get_bits() as usize;
69 self.io.write_buf(b"RIFF")?;
70 self.io.write_u32le(0)?;
71 self.io.write_buf(b"WAVE")?;
73 self.io.write_buf(b"fmt ")?;
74 self.io.write_u32le(16)?;
75 self.io.write_u16le(0x0001)?; // PCM
76 self.io.write_u16le(u16::from(ainfo.get_channels()))?;
77 self.io.write_u32le(ainfo.get_sample_rate())?;
80 self.io.write_u32le(u32::from(ainfo.get_channels()) * ainfo.get_sample_rate())?;
81 self.io.write_u16le(u16::from(ainfo.get_channels()))?; // block align
82 self.io.write_u16le(8)?;
84 self.io.write_u32le(2 * u32::from(ainfo.get_channels()) * ainfo.get_sample_rate())?;
85 self.io.write_u16le(u16::from(2 * ainfo.get_channels()))?; // block align
86 self.io.write_u16le(16)?;
89 self.io.write_buf(b"data")?;
90 self.io.write_u32le(0)?;
92 self.data_pos = self.io.tell();
95 /// Writes audio data.
96 pub fn write_frame(&mut self, abuf: NABufferType) -> ByteIOResult<()> {
98 NABufferType::AudioU8(ref buf) => {
99 write_data!(self.io, buf, write_byte);
101 NABufferType::AudioI16(ref buf) => {
102 write_data!(self.io, buf, write_s16);
104 NABufferType::AudioI32(ref buf) => {
105 write_data!(self.io, buf, write_s32);
107 NABufferType::AudioF32(ref buf) => {
108 write_data!(self.io, buf, write_f32);
110 NABufferType::AudioPacked(ref buf) => {
111 self.io.write_buf(buf.get_data().as_slice())?;
119 impl<'a> Drop for WavWriter<'a> {
120 #[allow(unused_variables)]
122 let size = self.io.tell();
123 if (self.data_pos > 0) && (size >= self.data_pos) {
124 let res = self.io.seek(SeekFrom::Start(4));
125 let res = self.io.write_u32le((size - 8) as u32);
126 let res = self.io.seek(SeekFrom::Start(self.data_pos - 4));
127 let res = self.io.write_u32le((size - self.data_pos) as u32);